fixup! ci: Default clang build

Author: KrystalDelusion

.github/workflows/test-linux.yml

@@ -13,6 +13,7 @@ jobs:
     runs-on: ${{ matrix.os.id }}
     env:
       CC: ${{ matrix.compiler }}
+      CXX: ${{ matrix.compiler }}
       CXXSTD: ${{ matrix.cpp_std }}
     strategy:
       matrix:
@@ -77,7 +78,7 @@ jobs:
           mkdir build
           cd build
           make -f ../Makefile config-${CC%%-*}
-          make -f ../Makefile -j$procs CXXSTD=$CXXSTD CC=$CC CXX=$CC LD=$CC
+          make -f ../Makefile -j$procs CXXSTD=$CXXSTD CC=$CC CXX=$CXX LD=$CC
 
       - name: Compress build
         shell: bash